
PROTECTION PRODUCTS
SDC36
TVS Diode Array for
Proximity Switch Input Protection
Description
The SDC36 is a high-surge transient voltage suppressor (TVS) optimized for protection of sensitive digital
sensors used in proximity switches and industrial
control applications. The SDC36 protects the components from over-voltages caused by electrostatic
discharge (ESD), electrical fast transients (EFT), and
tertiary lightning.
The unique design of the SDC36 incorporates two TVS
diodes in a compact SOT23 package for applications
where board space is at a premium. The single package provides protection for the I/O line and power
supply rail with high surge capabilities (2 Amps at
tp=1.2/50us) and an exceptionally low clamping
voltage of <45V.
The SDC36 replaces up to two large discrete diodes
providing the designer an easy to implement integrated
solution. The features of the SDC36 are ideal for
protection of two, three, and four wire DC high-side
proximity switches.
Features
u 350 watts peak pulse power (tp = 8/20µs)
u Transient protection for data & power lines to
IEC 61000-4-2 (ESD) 15kV (air), 8kV (contact)
IEC 61000-4-4 (EFT) 40A (5/50ns)
IEC 61000-4-5 (Lightning) 2A (1.2/50µs)
u Replaces two discrete devices
u Low clamping voltage
u Low leakage current
u High surge capability
u Solid-state silicon avalanche technology
Mechanical Characteristics
u JEDEC SOT23 package
u Molding compound flammability rating: UL 94V-0
u Marking : DC36
u Packaging : Tape and Reel per EIA 481
Applications
u Two, Three, and Four Wire DC High-Side Proximity
Switches
u Digital Sensor Input Protection
u Industrial Controls
u 24V - 33V DC Supply Protection
Circuit Diagram Schematic & PIN Configuration
SOT23 (Top View)
Revision 9/2000
1
www.semtech.com

PROTECTION PRODUCTS
Absolute Maximum Rating
SDC36
gnitaRlobmySeulaVstinU
)sµ02/8=pt(rewoPesluPkaePP
tnerruCesluPkaeP)sµ05/2.1=pt(I
erutarepmeTgniredloSdaeLT
erutarepmeTgnitarepOT
erutarepmeTegarotST
Electrical Characteristics
63CDS
retemaraPlobmySsnoitidnoCmuminiMlacipyTmumixaMstinU
egatloVffO-dnatSesreveRV
egatloVnwodkaerBesreveRV
tnerruCegakaeLesreveRI
kp
)sµ05/2.1=pt(rewoPesluPkaePP
)su001=pt(tnerruCdrawroFkaePevititepeR-noNI
MWR
RB
R
I
t
V
MWR
,Am1=63V
C°52=T,V33= 5Aµ
kp
PP
XAMSF
L
J
GTS
1ot2niPro1ot3niP33V
053sttaW
002sttaW
4A
4A
).ces01(062C°
521+ot55-C°
051+ot55-C°
tnerruCegakaeLesreveRI
egatloVdrawroFV
egatloVgnipmalCV
)TOH(R
F
C
V
MWR
I
F
I
PP
C°58=T,V33=52Aµ
,Am001=3.1V
,A2=
sµ05/2.1=pt
ecnaticapaCnoitcnuJC
j
V
R
zHM1=f,V0=54Fp
54V
2ã 2000 Semtech Corp.
www.semtech.com

PROTECTION PRODUCTS
PROTECTION PRODUCTS
Typical Characteristics
SDC36
Non-Repetitive Peak Pulse Power vs. Pulse Time
10
(kW)
PP
1
0.1
Peak Pulse Power - P
0.01
0.1 1 10 100 1000
Pulse Duration - tp (µs)
Pulse Waveform Clamping Voltage vs. Peak Pulse Current
110
100
90
80
70
PP
60
50
40
Percent of I
30
20
10
0
0 5 10 15 20 25 30
-t
e
Time (µs)
td = IPP/2
Waveform
Parameters:
tr = 8µs
td = 20µs
Power Derating Curve
110
100
90
PP
80
70
60
50
40
30
% of Rated Power or I
20
10
0
0 25 50 75 100 125 150
Ambient Temperature - T
60
55
(V)
C
50
45
40
35
Clamping Voltage - V
30
25
11.522.533.544.555.566.577.5
Peak Pulse Current - I
(oC)
A
Bidirectional
(Pin 1 to 2)
(A)
PP
Unidirectional
(pin 3 t o 1 & 3 t o 2)
Waveform
Parameters:
td = 20
tr = 8µs
s
Forward Voltage vs. Forward Current
3
2.5
(V)
F
2
1.5
1
Forward Voltage - V
0.5
0
0123456789101112
Forward Current - I
(A)
F
ã 2000 Semtech Corp.
Waveform
Parameters:
tr = 8µs
td = 20µs
3
www.semtech.com

PROTECTION PRODUCTS
Applications Information
Device Connection for Protection of Two, Three, and
Four Wire Proximity Switches
Digital sensors help to bridge the gap between the
physical world and the digital world in applications such
as computer controlled factory automation. In such
environments, transient voltages can easily disrupt or
damage sensitive sensor inputs. The SDC36 provides
transient voltage protection for the digital sensors to
ensure their operation is not disrupted by the physical
world.
The SDC36 is designed to meet the high surge capability and low clamping voltage needed to protect the
ASIC and control logic used in proximity switches. The
SDC36 provides protection for the power and I/O lines.
Typical configurations for the protection of two, three,
and four wire switches are as follows:
SDC36
2-Wire DC Proximity Switch Application
3-Wire DC Proximity Switch Application
1. Two-Wire Switch: Connect pin 1 to the I/O line and
pin 2 to the DC supply (since the device is symmetrical,
these connections can be reversed). Pin 3 is not
connected.
2. Three-Wire Switch: Either pin 1 or pin 2 is connected to the I/O line with the other connected to
ground. Pin 3 must be connected to the DC supply.
3. Four-Wire Switch: Two device are required to
protect four wire switches. Pin 3 of each device is
connected to the DC supply line. Pins 1 & 2 are
connected to the I/O lines & ground as shown.
4-Wire DC Proximity Switch Application
4ã 2000 Semtech Corp.
www.semtech.com

PROTECTION PRODUCTS
PROTECTION PRODUCTS
Outline Drawing - SOT23
SDC36
Land Pattern - SOT23
Note 1 : Grid placement courtyard is 8 x 8 elements (4mm x 4mm) in accordance with the international grid detailed in IEC
Publication 97.
ã 2000 Semtech Corp.
5
www.semtech.com

PROTECTION PRODUCTS
Ordering Information
SDC36
rebmuNtraP
CT.63CDSV33000,3hcnI7
GT.63CDSV33000,01hcnI31
gnikroW
egatloV
leeRrepytQeziSleeR
Contact Information
Semtech Corporation
Protection Products Division
652 Mitchell Rd., Newbury Park, CA 91320
Phone: (805)498-2111 FAX (805)498-3804
6ã 2000 Semtech Corp.
www.semtech.com